This invention relates to a system which mixes water with a fully activated polymer, for use in large scale water treatment and the like.
Polymers (actually water soluble polyelectrolytes) are commonly used in the treatment of water to remove suspended solids. In their inactive state, emulsion polymers are coiled. However, they become activated when suspended in water, so that they uncoil to expose positively and negatively charged sites. U.S. Pat. No. 4,522,502, entitled "Mixing and Feeding Apparatus" (the '502 patent), assigned to the same assignee as this application, discloses an apparatus for activating the polymers. These uncoiled polymers are extremely long, having millions of sites which attract charged particles suspended in the water to be treated.
The apparatus described in the '502 patent is capable of producing fully activated polymer of up to 2% concentration, at a rate of between 0.067 and 8 gallons per minute (GPM). Much higher flow rates may be necessary in certain installations. The same principles described in the '502 patent could be employed to make an apparatus which would deliver the activated and diluted polymer at a greater rate, but such an apparatus would be expensive and unwieldy. In these installations requiring high delivery rates, concentrations much lower than 2% can be effectively employed. As a matter of fact, a solution of high concentration, such as 2% is much too viscous to be usable in many water treatment facilities even though the polymer molecules are fully activated. This is because such a solution will ordinarily have a viscosity so great that it will not readily disperse in the stream being treated.